1. Field of the Invention
The present invention relates to a steel ring adjustment structure of a wheel cover, more particularly one, which allows the wheel cover to be firmly held on a wheel without risk of falling off even when the original steel ring used thereon is replaced with a new one having a different size from the original one.
2. Brief Description of the Prior Art
Wheel covers are secured on wheels to make the wheels more pleasant-looking. Referring to FIGS. 7 and 8, a conventional wheel cover 4 has several securing parts 41 equidistantly spaced apart near to an edge thereof, which each have a holding space 411 on an inward side. A first one of the securing parts 41 is formed with a hole 412 on one end, and two holes 413 and 414 on the other ends, which are at different distance from the surface of the wheel cover 4, and have different lengths. A C-shaped steel ring 42 is inserted in the hole 412 at one of the free ends, and one of the holes 413 and 414 at the other free end, and fitted in the holding spaces 411 such that the free ends of the securing parts 41 are radially outwardly displaced, and the securing parts 41 are tightly pressed against an inward edge of a wheel to prevent the wheel cover 4 from falling off. When the steel ring 42 is replaced with a new one having a different size from the original one 42, the new steel ring can outwardly displace the free ends of the securing parts 41 effectively by choosing and using a suitable one among the holes 413 and 414 for connection.
Referring to FIGS. 9 and 10, another conventional wheel cover 5 has several securing parts 51 equidistantly spaced apart near to an edge thereof, which each have a holding space 511 on an inward side. A first one of the securing parts 51 has a hole 512 on each of two ends thereof, and a hole 513 on each of the two ends thereof; the holes 513 and 512 are at different distance from the surface of the wheel cover 4, and have different lengths. A C-shaped steel ring 52 is inserted in chosen ones of the holes 512, 513 at two free ends thereof such that the free ends of the securing parts 51 are radially outwardly displaced, and the securing parts 51 are tightly pressed against an inward edge of a wheel to prevent the wheel cover 5 from falling off. Because the holes 512 and 513 have different lengths, steel rings of different sizes can be used on the wheel cover 5 by choosing and using suitable ones among the holes 512 and 513 for connection with the steel ring 52.
However, the different-length holes 512 and 513 are at different distance from the surface of the wheel cover 5, moment arms of force will be different when steel rings are inserted in different holes 512, 513; a steel ring inserted in the holes 513 will have a shorter moment arm of force, and in turn the steel ring's moment of force won't be great enough to outwardly displace the free ends of the securing parts 51 effectively. And, the first conventional wheel cover also has the same disadvantage.